A high performance multilayer film for packaging

ABSTRACT

A high-performance multilayer film for packaging, the structure being: BL/TIE/PO1/POX/PO3, obtained once by multilayer coextrusion and biaxial stretching, wherein: the total thickness of the multilayer film is 8 to 100 micrometers; the absolute value of the difference of the solubility parameters between the PO1 and PO3 layer materials is ≥0.1 and ≤0.5, and the absolute value of the difference of the cohesive energy density is ≥3, and ≤5; the solubility parameter and cohesive energy density of the POX bridge material are based on one of the PO1 and PO3 layer materials, and it&#39;s transitioned to the other in a gradient way; the absolute value of the difference of the solubility parameters between adjacent layers from the PO1 layer to the POX bridge and the PO3 layer is ≤0.1(J·cm−3)1/2, and the absolute value of the difference of the cohesive energy density is ≤3 J/cm3.

TECHNICAL FIELD

The present invention relates to the technical field of multilayerfilms, particularly to a high-performance multilayer film for packaging.The multilayer film can be applied to vacuum packaging, gas packaging,modified atmosphere packaging, high temperature cooking packaging,aseptic packaging, and coating, printing and composite substrates, etc.

BACKGROUND OF INVENTION

Multilayer co-extruded film is the film made with several types ofpolymers by methods of co-extrusion blowing, casting or orientation. Asplastic packaging material, this kind of film is widely used in food,processed meat, daily necessity, cosmetics, chemical, pesticide andmilitary products etc. And it can realize the sealed flexible packagingof products and meet various packaging functions such as inflation orvacuuming, thermoforming, modified atmosphere packaging, hightemperature cooking packaging, aseptic packaging, etc, as well asproviding barrier function such as moisture, oxygen, oil and aromabarrier etc. in various circumstances.

In the food packaging industry, the vacuum packaging, gas packaging,modified atmosphere packaging, high temperature cooking packaging,aseptic packaging and coating, printing and composite substrates arewidely used. In the vacuum packaging, the food is put into the packagingbag, the air in the package bag is removed and the bag is sealed afterit reaches the predetermined vacuum degree with the main function toremove the oxygen to prevent the food from spoilage. In the gaspackaging, a single gas of nitrogen, carbon dioxide or oxygen or amixture of the two or three gases is charged after the vacuum-pumping.In the modified atmosphere packaging, the modified atmospherefresh-keeping gas (2 or 4 kinds of gases mixed according to thecharacteristics of the food characteristics) is used to replace the airin the packaging bag to change the external environment of the food inthe package, inhibit the growth and reproduction of bacteria, slow downthe metabolic rate of fresh food, and extend the refreshing time orshelf life of the food. The aseptic packaging refers to a packagingmethod to seal the products that have been sterilized and have reachedthe commercial sterility (liquid milk and dairy products, beverages,etc.) in a sterilized container, fill in the products in a sterileenvironment and keep the packaging containers sealed after the filling.The composite flexible packaging film has been simultaneously developedwith the vacuum packaging, gas packaging, modified atmosphere packagingand high temperature cooking packaging, aseptic packaging and coating,printing, composite substrate technology and the key to vacuumpackaging, gas packaging, modified atmosphere packaging and hightemperature cooking packaging, aseptic packaging and coating, printing,and composite substrate technology is to maintain the barrier functionand excellent heat-sealing property of the packaging film. In order toachieve the goal of environmental protection and production reduction,the multi-layer co-extrusion process is used to achieve zero emission ofVOCs and the biaxial stretching molding process is used to guarantee thestrength when the film is thin to a certain extent. However, as theprocessing characteristics of materials at different layers of themulti-layer high barrier film are different and the molding technologyfor simultaneous coextrusion and biaxial stretching under the sameprocess conditions is limited by the prior art, the interlayer peelstrength and heat-sealing property of the film cannot be guaranteed.

The prior art has the following problems: 1. The materials at differentlayers of the multi-layer high barrier film are different, and thestretching ratios of different materials are different, and when thematerial layer of the smaller stretching ratio is stretched to the sameratio as the material layer of the larger stretching ratio, theinterlayer peel strength is drastically lowered or it may even bedelaminated, and the material of the smaller stretching ratio is likelyto be torn; 2. The heat-sealing property is lowered after thestretching; 3. In order to make the stretched film have the sufficientheat-sealing property, the stretched film is usually laminated with aheat-sealing layer, but the dry composite solvent used in the laminationcontains the pollutant, which is unsafe for food and environmentallyunfriendly.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide a high-performancemultilayer film for packaging.

To achieve above object, the technical solution adopted in thisinvention is: a high-performance multilayer film for packaging, and theinnovation is: the structure of the multilayer film is as follows:

BL/TIE/PO1/POX/PO3   Structure (1)

In Structure (1), explicated from left to right:

-   BL represents an outer layer and the material is polyamide, or    polyester or ethylene-vinyl alcohol copolymer;-   TIE represents a bonding layer and the material is the maleic    anhydride grafted copolymer with the PO1 layer material as the    carrier;-   PO1 represents a main stretching layer, also known as a PO1 layer,    and the material is polyethylene or polypropylene;-   POX represents a stretching transition bridge, also known as a POX    bridge, and the material is any one or a mixture of at least two of    polyethylene, polypropylene, modified polyethylene and modified    polypropylene; X represents the number of layers, and X is 1, 2, 3,    . . . , but not 0;-   PO3 represents an inner layer, also known as a PO3 layer, and the    material is any one or a mixture of at least two of polyethylene,    polypropylene, modified polyethylene and modified polypropylene;-   The multilayer film in structure (1) is obtained once by multilayer    coextrusion and biaxial stretching, wherein, the biaxial stretching    is carried out by a two-step stretching method of longitudinal    stretching first and transverse stretching later;-   The total thickness of the multilayer film is 8 micrometers to 100    micrometers, the thickness of the PO1 layer is 30 to 60% of the    total thickness of the multilayer film; the thickness of the POX    layer is 10 to 20% of the total thickness of the multilayer film;    the thickness of the PO3 layer is 8 to 20% of the total thickness of    the multilayer film;-   The selection requirements for the density of materials of the PO1    layer, the POX layer and the PO3 layer are as follows: When the PO1    layer is polyethylene, the density of the PO1 layer is 0.87˜0.97    g/cm³; when the PO1 layer is polypropylene, the density of the PO1    layer is 0.86˜0.91 g/cm³; the density of the POX bridge is 0.86˜0.97    g/cm³, and the density of the PO3 layer is 0.87˜0.97 g/cm³;-   The absolute value of the difference of the solubility parameters    between the PO1 layer and the PO3 layer material is greater than or    equal to 0.1(J·cm⁻³)^(1/2), and less than or equal to    0.5(J·cm⁻³)^(1/2), and the absolute value of the difference of the    cohesive energy density between the PO1 layer and the PO3 layer    material is greater than or equal to 3 J/cm³, and less than or equal    to 5 J/cm³; the solubility parameter and the cohesive energy density    of the POX bridge material are based on one of the PO1 layer    material and the PO3 layer material, and it's transitioned to the    other in a gradient way;-   The absolute value of the difference of the solubility parameters    between adjacent layers from the PO1 layer to the POX bridge and to    the PO3 layer is less than or equal to 0.1(J·cm⁻³)^(1/2), and    meanwhile, the absolute value of the difference of the cohesive    energy density between adjacent layers from the PO1 layer to the POX    bridge and to the PO3 layer is less than or equal to 3 J/cm³.

The above described technical solution is explained as follows:

-   1. In above described technical solution, the solubility parameter    and the cohesive energy density of the POX bridge material are based    on one of the PO1 layer material and the PO3 layer material, and    it's transitioned to the other in an increment or decrement way;

2. In above described technical solution, the solubility parameter andthe cohesive energy density of the POX bridge material are based on oneof the PO1 layer material and the PO3 layer material, and it'stransitioned to the other in a V-shaped gradient way;

3. In above described technical solution, the solubility parameter andthe cohesive energy density of the POX bridge material are based on oneof the PO1 layer material and the PO3 layer material, and it'stransitioned to the other in an M-shaped gradient way;

4. In above described technical solution, the solubility parameter andthe cohesive energy density of the POX bridge material are based on oneof the PO1 layer material and the PO3 layer material, and it'stransitioned to the other in a W-shaped gradient way;

5. In the present invention, the solubility parameter (referred to asSP) is a physical constant for measuring the compatibility of a polymermaterial under processing conditions (including liquid state of rubberand plastic under processing conditions).

The cohesive energy density is the energy E (cohesive energy) requiredfor the vaporization of 1 mol of condensate per unit volume V toovercome the intermolecular force. It is a physical variable evaluatingthe magnitude of the intermolecular forces and mainly reflecting theinteraction between the groups. In general, the greater the polarity ofthe groups contained in the molecules, the greater the force between themolecules, and the greater the corresponding cohesive energy density;and vice versa.

The physical meaning of the solubility parameter is the square root ofthe cohesive energy density per unit volume of the material:SP=(E/V)^(1/2), wherein, SP is the solubility parameter, E is thecohesive energy, V is the volume, and E/V is the cohesive energydensity.

The technical principle and advantages of the present invention:understanding the solubility parameter is to grasp the degree ofcompatibility between different polymers, and provide a basis forsuccessful blending. The closer the solubility parameters of the twohigh polymer materials are, the better the blending effect is. If thedifference between the two exceeds 0.5, it is generally difficult toblend evenly, and it is necessary to add the solubilizer. The functionof the solubilizer is to reduce the surface tension of the two phases sothat the surface at the interface is actuated, thereby increasing thedegree of compatibility. The solubilizer is often a polymer that acts asa bridge intermediary. In the present invention, the stretchingtransition bridge acts as a solubilizer and a bridge intermediary.

Two important factors influencing the multilayer co-extrusion biaxialstretching of multilayer film are the solubility parameters and densityof interlayer materials, and the cohesive energy density is the cohesiveenergy per unit volume of the material, and the cohesive energy densityis proportional to the material density and the melting point/softeningtemperature of the material. The invention is based on the same orsimilar cohesive energy density and solubility parameter of the polymeras the basis for setting the stretching transition bridge (POX bridge),that is, in accordance with the basic rule of like dissolves like oforganics. The closer the solubility parameters and cohesive energydensity of the two high polymer materials are, the better the blendingeffect is. The difference between the solubility parameters and thecohesive energy density of the interlayer material is narrowed throughthe stretching transition bridge to eliminate or weaken the internalstress between the structural layers, improve the peel strength andheat-sealing strength, and realize the biaxial stretching of themultilayer co-extruded film.

In the present invention, when the absolute value of the difference ofthe solubility parameters between the PO1 layer and the PO3 layermaterial is greater than or equal to 0.1(J·cm⁻³)^(1/2), and less than orequal to 0.5 (J·cm⁻³)^(1/2), and the absolute value of the difference ofthe cohesive energy density is greater than or equal to 3 J/cm³, andless than or equal to 5 J/cm³, the present invention can simultaneouslysatisfy the requirements of the transition of compatibility from the PO1layer to the PO3 layer, the biaxial stretching of the multilayerco-extruded film and the thickness of the stretching transition bridgeaccounting for 10˜20% of the total thickness of the multilayer filmthrough the POX bridge. When the absolute value of the difference of thesolubility parameters between the PO1 layer and the PO3 layer materialis greater than 0.5 (J·cm⁻³)^(1/2), and the absolute value of thedifference of the cohesive energy density is greater than 5 J/cm³, thecompatibility between the PO1 layer and the PO3 layer material is poor,and at this time, it cannot simultaneously satisfy the requirements ofcompatibility, biaxial stretching, and the thickness of the stretchingtransition bridge accounting for 10˜20% of the total thickness of themultilayer film through the stretching transition bridge of the presentinvention. When the absolute value of the difference of the solubilityparameters between the PO1 layer and the PO3 layer material is less than0.1 (J·cm⁻³)^(1/2), or/and the absolute value of the difference of thecohesive energy density is less than 3 J/cm³, the stretching transitionbridge is not required.

The present invention increases the strength by the biaxial stretchingprocess to make ordered arrangement of molecules.

SPECIFIC EMBODIMENT

With reference to the embodiments, the present invention will bedescribed in detail: Embodiment 1: In the structure of multilayer film,PO1 is polypropylene; POX is high density polyethylene/linear lowdensity polyethylene+high density polyethylene/linear low densitypolyethylene+ethylene-octene copolymer/ethylene-octene copolymer, thenumber of layers is four; PO3 is polypropylene. See Table 1:

TABLE 1 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9000 8.10 0.1065.61 1.61 (homopolymerization) PP POX High density 0.9600 8.00 64.00polyethylene HDPE Linear low density 0.9250 7.94 0.06 63.04 0.96polyethylene LLDPE + high density polyethylene Linear low density 0.94607.98 0.04 63.68 0.64 polyethylene LLDPE + ethylene- octene copolymerEthylene-octene 0.9190 7.89 0.09 62.25 1.43 copolymer PO3 Polypropylene0.9050 7.80 0.09 60.84 1.41 (copolymerization) PPThe density, solubility parameter and cohesive energy density of eachpolymer can be seen in Table 1, and the absolute value of the differenceof the solubility parameters between the PO1 layer and the PO3 layermaterial is 0.30(J·cm⁻³)^(1/2),0.1(J·cm⁻³)^(1/2)<0.30(J·cm⁻³)^(1/2)<0.5(J·cm⁻³)^(1/2), and the absolutevalue of the difference of the cohesive energy density between the PO1layer and the PO3 layer material is 4.773 J/cm³, 3 J/cm³<4.773 J/cm³<5J/cm³, which meets the conditions for setting the stretching transitionbridge. The stretching transition bridge POX is a four-layer structure,and the solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material in a V-shaped way;

-   The absolute value of the difference of the solubility parameters    between adjacent layers from the PO1 layer to the POX bridge and to    the PO3 layer is less than or equal to 0.1(J·cm⁻³)^(1/2), and    meanwhile, the absolute value of the difference of the cohesive    energy density between adjacent layers from the PO1 layer to the POX    bridge and to the PO3 layer is less than or equal to 3 J/cm³.

The following embodiments are presented in a table, and no more detaileddescription is made by text to save space.

Embodiment 2: In the structure of multilayer film, PO1 is polypropylene;POX is high density polyethylene/linear low density polyethylene/highdensity polyethylene, the number of layers is three; PO3 isethylene-octene copolymer. See Table 2:

TABLE 2 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9000 8.10 0.1065.61 1.61 (homopolymerization) POX High density 0.9600 8.00 64.00polyethylene HDPE Linear low density 0.9250 7.95 0.05 63.20 0.80polyethylene LLDPE High density 0.9200 7.90 0.05 62.41 0.79 polyethyleneHDPE PO3 Ethylene-octene 0.9100 7.80 0.10 60.80 1.61 copolymerThe solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

Embodiment 3

In the structure of multilayer film, PO1 is high density polyethylene;POX is linear low density polyethylene/low density polyethylene, thenumber of layers is two; PO3 is ethylene-octene copolymer. See Table 3:

TABLE 3 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 High density 0.9600 8.00 0.05 64.000.80 polyethylene HDPE POX Linear low 0.9250 7.95 0.05 63.20 0.79density polyethylene LLDPE Low density 0.9200 7.90 62.41 polyethyleneLDPE PO3 Ethylene-octene 0.9100 7.80 0.10 60.80 1.61 copolymerThe solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

Embodiment 4

In the structure of multilayer film, PO1 is high density polyethylene;POX is linear low density polyethylene/high density polyethylene+lowdensity polyethylene, the number of layers is two; PO3 is high densitypolyethylene+polypropylene. See Table 4:

TABLE 4 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 High density 0.9600 8.00 0.05 64.000.80 polyethylene HDPE POX Linear low 0.9250 7.95 0.05 63.20 0.79density polyethylene LLDPE High density 0.9200 7.90 62.41 polyethyleneLDPE + low density polyethylene LDPE PO3 High density 0.9188 7.85 0.0561.62 0.79 polyethylene HDPE + polypropylene PPThe solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

Embodiment 5

In the structure of multilayer film, PO1 is polypropylene; POX is highdensity polyethylene/linear low density polyethylene/low densitypolyethylene, the number of layers is three; PO3 is ethylene-octenecopolymer. See Table 5:

TABLE 5 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9000 8.10 0.1065.01 1.61 (homopolymerization) POX High density 0.9600 8.00 0.05 64.000.80 polyethylene HDPE Linear low density 0.9250 7.95 63.20 polyethyleneLLDPE Low density 0.9200 7.90 0.05 62.41 0.79 polyethylene LDPE PO3Ethylene-octene 0.9100 7.80 0.10 60.80 1.61 copolymerThe solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

Embodiment 6

In the structure of multilayer film, PO1 is polypropylene; POX is highdensity polyethylene/linear low density polyethylene+ethylene-octenecopolymer, the number of layers is two; PO3 is ethylene-octenecopolymer. See Table 6:

TABLE 6 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9 8.1 0.1 65.611.61 (homopolymerization) PP POX High density 0.96 8 0.1 64 0.96polyethylene HDPE + Linear low density 0.9198 7.9 63.04 polyethyleneLLDPE + ethylene- octene copolymer PO3 Ethylene-octene 0.91 7.8 0.160.84 2.2 copolymer PPThe solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

Embodiment 7

In the structure of multilayer film, PO1 is polypropylene; POX is highdensity polyethylene+ethylene-octene copolymer/ethylene-octenecopolymer/linear low density polyethylene+ethylene-octene copolymer, thenumber of layers is three; PO3 is polypropylene. See Table 7:

TABLE 7 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9000 7.8 0.05 60.840.78 (homopolymerization) PP POX High density 0.9500 7.85 0.05 61.620.78 polyethylene HDPE + ethylene-octene copolymer Ethylene-octene0.9100 7.8 60.84 copolymer Linear low density 0.9190 7.9 0.1 62.41 1.57polyethylene LLDPE + ethylene- octene copolymer PO3 Polypropylene 0.90887.995 0.095 63.92 1.51 (copolymerization) PP + modified polyethylene(EVA)The solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material in a V-shaped way.

Embodiment 8

In the structure of multilayer film, PO1 is polypropylene; POX ismodified polyethylene+high density polyethylene/linear low densitypolyethylene/linear low density polyethylene+modified polyethylene, thenumber of layers is three; PO3 is ethylene-octene copolymer. See Table8:

TABLE 8 Absolute value of the difference of the Absolute value ofcohesive the difference of energy the solubility density parametersCohesive between Solubility between adjacent energy adjacent Densityparameter layers density layers Layer Polymer (g/cm³) (J · cm⁻³)^(1/2)(J · cm⁻³)^(1/2) (J/cm³) (J/cm³) PO1 Polypropylene 0.9000 8.10 0.0565.61 0.81 (homopolymerization) PP POX Modified 0.9585 8.05 0.10 64.801.60 polyethylene (EVA) + high density polyethylene HDPE Linear lowdensity 0.9250 7.95 62.20 polyethylene LLDPE Linear low density 0.95007.85 0.10 61.62 1.58 polyethylene LLDPE + Modified polyethylene (EVA)PO3 Polypropylene 0.9100 7.80 0.05 60.84 0.78 (copolymerization) PP +modified polyethylene (EVA)The solubility parameter and the cohesive energy density of the POXbridge material are based on the PO1 layer material, and it'stransitioned to the PO3 layer material.

It should be noted that the above described embodiments are only forillustration of technical concept and characteristics of presentinvention with purpose of making those skilled in the art understand thepresent invention. The technicians in this art could make change on thebasis of the above embodiment, such as choosing different densities ofmaterials, choosing different activators, etc, and thus theseembodiments shall not limit the protection range of present invention.The equivalent changes or modifications according to spiritual essenceof present invention shall fall in the protection scope of presentinvention.

1. A high-performance multilayer film for packaging, wherein: thestructure of the multilayer film is as follows:BL/TIE/PO1/POX/PO3   Structure (1) In Structure (1), explicated fromleft to right: BL represents the outer layer and the material ispolyamide, or polyester or ethylene-vinyl alcohol copolymer; TIErepresents the bonding layer and the material is the maleic anhydridegrafted copolymer with the PO1 layer material as the carrier; PO1represents a main stretching layer, also known as a PO1 layer, and thematerial is polyethylene or polypropylene; POX represents a stretchingtransition bridge, also known as a POX bridge, and the material is anyone or a mixture of at least two of polyethylene, polypropylene,modified polyethylene and modified polypropylene; X represents thenumber of layers, and X is 1, 2, 3, . . . , but not 0; PO3 represents aninner layer, also known as a PO3 layer, and the material is any one or amixture of at least two of polyethylene, polypropylene, modifiedpolyethylene and modified polypropylene; The multilayer film instructure (1) is obtained once by multilayer coextrusion and biaxialstretching, wherein, the biaxial stretching is carried out by a two-stepstretching method of longitudinal stretching first and transversestretching later; The total thickness of the multilayer film is 8micrometers to 100 micrometers, the thickness of the PO1 layer is 30 to60% of the total thickness of the multilayer film; the thickness of thePOX layer is 10 to 20% of the total thickness of the multilayer film;the thickness of the PO3 layer is 8 to 20% of the total thickness of themultilayer film; The selection requirements for the density of materialsof the PO1 layer, the POX layer and the PO3 layer are as follows: Whenthe PO1 layer is polyethylene, the density of the PO1 layer is 0.87˜0.97g/cm³; when the PO1 layer is polypropylene, the density of the PO1 layeris 0.86˜0.91 g/cm³; the density of the POX bridge is 0.86˜0.97 g/cm³,and the density of the PO3 layer is 0.87˜0.97 g/cm³; The absolute valueof the difference of the solubility parameters between the PO1 layer andthe PO3 layer material is greater than or equal to 0.1(J·cm⁻³)^(1/2),and less than or equal to 0.5(J·cm⁻³)^(1/2), and the absolute value ofthe difference of the cohesive energy density between the PO1 layer andthe PO3 layer material is greater than or equal to 3 J/cm³, and lessthan or equal to 5 J/cm³; the solubility parameter and the cohesiveenergy density of the POX bridge material are based on one of the PO1layer material and the PO3 layer material, and it's transitioned to theother in a gradient way; The absolute value of the difference of thesolubility parameters between adjacent layers from the PO1 layer to thePOX bridge and to the PO3 layer is less than or equal to0.1(J·cm⁻³)^(1/2), and meanwhile, the absolute value of the differenceof the cohesive energy density between adjacent layers from the PO1layer to the POX bridge and to the PO3 layer is less than or equal to 3J/cm³.
 2. The high-performance multilayer film for packaging of claim 1,wherein: the solubility parameter and the cohesive energy density of thePOX bridge material are based on one of the PO1 layer material and thePO3 layer material, and it's transitioned to the other in an incrementor decrement way;
 3. The high-performance multilayer film for packagingof claim 1, wherein: the solubility parameter and the cohesive energydensity of the POX bridge material are based on one of the PO1 layermaterial and the PO3 layer material, and it's transitioned to the otherin a V-shaped gradient way;
 4. The high-performance multilayer film forpackaging of claim 1, wherein: the solubility parameter and the cohesiveenergy density of the POX bridge material are based on one of the PO1layer material and the PO3 layer material, and it's transitioned to theother in a M-shaped gradient way;
 5. The high-performance multilayerfilm for packaging of claim 1, wherein: the solubility parameter and thecohesive energy density of the POX bridge material are based on one ofthe PO1 layer material and the PO3 layer material, and it's transitionedto the other in a W-shaped gradient way.